Locking cooperating threaded element



June 9, 192.1; ,,,5 LADD 7 1,809,301

LOCKING COOPERATING THREADED ELEMENT Y Filed Jan; 15. 1950 i4 ATTORNEY Patented June 9, 931

1,809,301 j p i f UNITED STATES? PATENT i JAMES B. LADD, or. ARDMORE, rnmvsvnvhnra LOCKING GOOPERATING TI-IBEQDED. E nMnnr I 1 Application filed January 15, 1930. Serial "Ne. 420,353.

This invention relatesto means for locking cooperating threaded elements, such as a nut to a bolt, for the purpose of holding the nut from working loose, and refers particularly 5 to means for holding the threaded elements against relative rotation in either direction up to a predetermined rotary torque.

A further object is to provide locking means which will be simple andinexpensive and which will not require extreme accuracy of parts. g

Other objects and advantages of the construction will be seen from the description following, and the accompanying drawmgs which illustrate, merely by way of example,

suitable embodiments of the invention.

Fig. 1 is a plan view of a nut on a bolt with a locking pawl; w

Fig. 2 is a part sectlon and part elevation of the device shown in Fig. 1.

Fig. 8 is a plan view showing amodification.

Fig. 4 is a part section and part elevation enlarged scale of another modification. Fig. 10 is a part section and part elevatio of the device shown in Fig. 9.

h Fig. 11 is a fragmentary plan-view on an enlarged scale of another modification.

. Fig. 12' is a part section and part elevation of the device shown in Fig. 11. r

Similar numerals refer to similar parts throughout the several views;

seated and confined in a recess in the nut.

The pawl, which is formedof resilient material, is adapted to move angularly with respect to theaxis of the nut and is so located opposite direction;

or bore-bf the nut, and when the "nut is 7 Broadly described, my invention comprises a pawl 22, one end ofv which 'is rotatablyand confined that when the nut is turned onto the bolt the free end of the pawl will be brought into forcible contact with thethread on thebolt and will resist the rotation of the -nut. in the reverse directionup to 'a-prcas determined torque, and w ill yield, when the torque is increased above the predetermined amount, to be moved angularly by thereverse rotation-of thenut into. a-position'i'n which it will resist the; rotation of the nut in the In generahwhen the'nut. 20, with my looking "device, isput on a bolt 21 witlra righthand thread,-the;pawl 22 will automatically be brought into the position in which it is shown in Fig.-

by the'rotationof the nut 'in'the direction of the arrowshowm and'if the nut is forcibly turned in the reverse: ,7 "direction, the pawl will 'betmoved across the {I H fradial .line into th showninFig; 3.1

V y position in which it is When the pawllis hue 11mm of its-free angular movement, in-either direction, its

free end 29 eXtends into the, threaded *hole rotated ontolthe bo'ltsaid free-end is forced beyond said free angular position and is brought into forcible contact with the thread on the bolt by the fiexure of the "pawl.

In accordance with invention the'pawl is always free to rotate in'its seat through a slight ang le either side of a radial line drawn through theaxis of the seat andthe center of the nut, butitsangular movement is always positively limited by suitable abutmentssuch 4 as 24:, shown'i'n Figs. 1, 5 and 11, or by abutments 25, shown in Figs. 3, 7 and 9. I i

When the nut has been rotated the pawl is forcibly in contact with the thread tated in the reverse direction, with sufficient force to overcome the normal resistanceof the pawl, the pawl must pass a radial posi- V I r' tion in passing over to the position shown 1n *9: r

Fig. 3, and therefore, to permit the pawl .to

be ed by the rotation of the, nut from the 3 2' position shown in Fig. 1 to the position shown in Fig. 3, it is essential that the pawl mustbe shortened lengthwise, and this is accomon the bolt V in the direction of the arrow, asin Fig. 1, and '7 I 'on the bolt, it is evident that if the nut is roplished by flexure of the part of the pawl in the seat when pawls of the form shown in Figs. 1, 3, 5, 7.and 9 are used, and by fleXure of the pawl outside of the seat when a pawl of the form shown in Fig. 11 is used.

The pawl is confined in its seat by the edges of the seat being forced slightly over it, as shown at 30 in Figs. 2, 4i, 6, 8 and 12, or by other suitable means.

' 10 The free end of the pawl, which contacts with the thread on the bolt, is preferably of a cylindrical form, as shown in Fig. 11, but may be of any form adapted to holding the nut against rotation, either by friction or by biting into the thread, or both.

hat I claim is V 1,- ,A device for locking a nut to a bolt or the like comprising a pawl, one end of which is seated in a recess in a nut and confined g therein,ebut free to turn therein around an axis approximately parallel with the axis of the nut, the pawl extending from its seat into the bore of the nut, and means co-acting with the pawl to limit its free angular movement to a small angle to either side of a radial position relative to the nut, said limiting means causing the free end of thepawl to lockingly engage thethread on the bolt when the pawl is flexed beyond either limit of itsfree angular motion. a.

2; A device for looking a nut to a bolt or the like comprising apawl, one end'of which is I seated in arecess iria nut and confined there- 7 in, but free to turn therein around an axis approximately parallel with the axis ofthe nut, the pawl extending-from its seat into the bore of the nut, means co-acting with the pawl to limit its free angularmovement to a small angle either side of a radial position relative in to the nut, said limiting'means causing the free end of the pawl to lockingly engage the thread on'the bolt when the pawl is flexed beyond either limit of its free angular motion, and meanspermitting the free end of a the pawl to move toward its seat, when the nut is forcibly rotated in the reverse direction, to permit the pawl to be turned ,angularly past a radial position relative to the nut to engage the thread on the bolt on the ,opposie sideto resist rotation of the nut in the reverse direction.

' JAMES B. LADD; 

